Undergo is a verb.
Underwent is a verb, the past tense of undergo.
Speech orientation is when someone has a speech disorder or needs to undergo therapy to fix it. They would undergo simple tasks such learning to pronounce simple words in the correct manner and the tasks will gradually build up.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "twirl" is a verb.
The part of speech for "explicit" is an adjective.
The part of speech for "indefinite" is an adjective.